Area Converter
Convert an area between square centimeters, square meters, square kilometers, hectares, square feet, square yards, acres and square miles — with the exact factor used and the land measures that go with it.
Exact defined factors: 1 acre = 43,560 ft², 1 ha = 10,000 m², 1 mi² = 2.589988110336 km².
Formula and calculation
Worked example
A quarter-acre lot is 1,011.7141 square meters. The factor line reads 1 acre = 4046.856422 m², so the arithmetic is 0.25 × 4046.856422 = 1011.714 m² — a plot about 32 m on a side, or roughly a tenth of a hectare.
What an acre actually looks like
Numbers like 4046.86 m² are hard to picture, so anchor them: a football (soccer) pitch inside the touchlines is about 7,140 m², roughly 1.76 acres; an American football field including both end zones is 5,351 m², or 1.32 acres; a typical suburban quarter-acre lot is 1,011.7 m². The hectare is the easier metric yardstick — 10,000 m², a square 100 m on a side, about two and a half acres. When a listing quotes one unit and the local planning rules another, convert both to the same unit before comparing anything.
What the results mean
- 1 acre =
- Your area converted to the target unit, using the exact defined measures (1 acre is exactly 4046.8564224 square meters).
- Conversion factor
- The one-way factor for this pair, so you can repeat the arithmetic by hand: value x factor = result.
- Reverse
- The same factor in the opposite direction, for converting a result back later.
Frequently asked questions
How big is an acre in feet?
43,560 square feet, which is a square about 208.7 ft on a side, or a strip one furlong by one chain (660 ft by 66 ft). It is just under 0.405 of a hectare, which is why acreage and hectares are often quoted together.
How many acres are in a hectare?
2.4710538 acres, because a hectare is 10,000 m² and an acre is 4046.8564224 m². One acre is 0.40468564224 hectares, so a 100 hectare farm is about 247 acres.
How many square feet are in a square meter?
10.7639104, so a 100 m² apartment is about 1,076 ft². The factor follows from 1 ft = 0.3048 m exactly: one square meter is 1 / 0.3048² square feet.
Why is a square mile 640 acres?
Because the US land survey grid was built that way: a section is one square mile, and each section is divided into 640 acres. In metric terms a square mile is 2.589988110336 km², a little over 2.5 km², so 259 hectares.